Exploring The Sky Flashcards
(29 cards)
How many times fainter is the Moon to the Sun?
Around a million times fainter
How many planets are visible to the naked eye and what are they?
5;
- Jupiter
- Venus
- Saturn
- Mars
- Mercury
Which two planets orbit inside that of the earth?
Mercury and Venus
Which 3 planets orbit outside that of the earth?
Jupiter, Mars & Saturn
When was Uranus discovered?
1781
When was Neptune discoered?
1846
Why do stars twinkle?
Distance and irregularities within the Earth’s atmosphere
How many stars are bright enough to be seen by the naked eye under good observing conditions?
Around 6,000
How many stars are estimated to be in the Galaxy?
2 x 10-11
Between which two planets is the asteroid belt that Ceres was found?
Mars & Jupiter
Which asteroid belt is Pluto found?
Kuiper
How frequently does Halley’s Comet return near to the sun?
Every 76 years
What creates the glow of a meteor?
When a body enters the atmosphere it becomes vaporised
What is an Aurorae?
When charged particles enter the earth’s atmosphere
Which stars are always above the horizon?
Circumpolar stars
What is the observer’s meridian?
The greatest altitude of a star above the horizon along the north-south line.
Which term is given to the seven stars that can always be seen from Glasgow and can be used as way of finding the Pole Star?
The Plough
How many arc seconds are in one degree?
3, 600
For an observer, the altitude of the Pole Star is about:
56 degrees
What does the declination of a star tell us?
How far north or south the celestial equator is
What is the declination of the Pole Star?
89.3 degrees
Johann Bayer (1603) introduced which star map?
Uranometria
How was Johann Bayer’s (1609) map of Uranometra labelled?
By their constellation and by a Greek letter. A being the brightest and getting smaller as the alphabet proceeds.
How did John Flamsteed (1725) label his stars?
He numbered stars in order of increasing right ascension.
